<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Navigation Bar Example</title>
<style>
    /* 基本样式 */
    body {
        font-family: Arial, sans-serif;
    }
    nav {
        background-color: #333;
    }
    nav ul {
        list-style-type: none;
        margin: 0;
        padding: 0;
        overflow: hidden;
    }
    nav li {
        float: left;
    }
    nav li a {
        display: block;
        color: white;
        text-align: center;
        padding: 14px 16px;
        text-decoration: none;
    }
    nav li a:hover {
        background-color: #111;
    }
    /* 下拉菜单样式 */
    .dropdown-content {
        display: none;
        position: absolute;
        background-color: #f9f9f9;
        min-width: 160px;
        box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
        z-index: 1;
    }
    .dropdown-content a {
        color: black;
        padding: 12px 16px;
        text-decoration: none;
        display: block;
        text-align: left;
    }
    .dropdown-content a:hover {
        background-color: #ddd;
    }
    .dropdown:hover .dropdown-content {
        display: block;
    }
</style>
</head>
<body>

<nav>
    <ul>
        <li><a href="#home">首页</a></li>
        <li><a href="#about">关于</a></li>
        <li class="dropdown">
            <a href="#services" class="dropbtn">消费者服务</a>
            <div class="dropdown-content">
                <a href="#">产品信息</a>
                <a href="#">商家信息</a>
                <a href="#">加入我们</a>
            </div>
        </li>
        <li><a href="#contact">商务中心</a></li>
        <li><a href="#blog">研究中心</a></li>
    </ul>
</nav>

</body>
</html>
